A power distribution system in accordance with the Power-over-Ethernet (PoE) standard uses Ethernet cables for supplying direct current (DC) voltage from power supply equipment (PSE) to powered devices (PD) which may be lighting devices. The PoE power distribution system is often operable in a normal operation mode and in a standby mode, wherein even in the standby mode the power consumption within the PoE power distribution system can be relatively high.
U.S. Pat. No. 6,909,921 B1 discloses a home automation system comprising entry/exit sensors for detecting movement through doorways that separate rooms in a home, room motion sensors for detecting room occupancy, spot sensors to detect occupancy of specific locations within the rooms, and house status sensors to detect the status of certain parameters of the home. A central controller communicates with the sensors and controlled objects over a communications network, wherein the central controller controls the controlled objects in response to the entry/exit sensors, room motion sensors, spot sensors and the house status sensors.
WO 2013/050970 A1 discloses a network switch operable to control supply of electrical power to a network device, wherein the network switch is configured to supply power to the device upon receiving a signal destined for the device and to continue to supply the power to the device whilst successive signals from the device are received within a period being smaller than a predetermined shut off period.
WO 2012/028979 A1 discloses an apparatus for powering an electrical consumer via a data connection, wherein the apparatus comprises a power supply for supplying power to the electrical consumer via the data connection, a data receiving unit for receiving data to be sent to the electrical consumer, and a controller for activating the supply of power to the electrical consumer via the data connection, if data to be sent to the electrical consumer have been received and the supply of power to the electrical consumer is deactivated.